zane9000 Posted March 7, 2006 Share Posted March 7, 2006 So I did some searching about EFI gas tanks and found some really good threads, but none that specificly address my question, so here we go: I just got my 1975 tank today that Im going to bolt into my 73z for my EFI conversion. I know There are 5 connections for hoses and one hole. I think the two connections on the top are vents, Two on the bottom are feed/return lines, the big one is the filler neck, but I dont know what the big hole in the side is for. Its about the same size as the filler neck connection, but its just a hole. It has 3 tabs around it. Im guessing maybe fuel sending unit? Anyone know? Quote Link to comment Share on other sites More sharing options...
spotfitz Posted March 7, 2006 Share Posted March 7, 2006 Fuel sending unit and fuel lines go in the hole where the tabs are. It's one plate that fits in that hole that has your fuel line connections and the power connections for the fuel sender. The rest of the holes, minus the fuel filler, is for vapor recovery/vent. Haynes/Chilton manual would have all this information, since they cover a wide range of years. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 7, 2006 Share Posted March 7, 2006 Sounds like the sender hole. I don't know if they're the same, but the 240 sender has a locking ring which screws in and locks the sender down. If they aren't the same you might have a bit of trouble finding that little locking ring if it isn't there... Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 7, 2006 Author Share Posted March 7, 2006 Haynes/Chilton manual would have all this information, since they cover a wide range of years. Actually I couldnt find any useful info in my Chilton manual for any car other than the 300zx. I shall look again though... Quote Link to comment Share on other sites More sharing options...
spotfitz Posted March 7, 2006 Share Posted March 7, 2006 Sorry. You are correct. The only one I can find is for the 300ZX, but about the only difference(excluding the shape) is the location of the sender and it being combined with the fuel inlet/outlet/evap. In this pic you are looking at the front of the tank, towards the differential, and the sender on the '70-'76 would be on this side facing the differential, but closer to the passenger side. Note the filler location in the pic for reference. On '77-'83 it is located on top and later '84-'96 (like the pic) I'm pretty sure they separated them and inserted the pump in the tank. As jmortensen mentioned, there is a ring that holds the sender in the hole with an o-ring for a seal. I know that the sender hole size appeared to be the same between my early '74 and my early '77. Whether the sender has the same size ring or more specifically the Exact same sender, I don't know. http://www.autozone.com/images/cds/gif/large/0900823d801d1bd6.gif Quote Link to comment Share on other sites More sharing options...
technicalninja Posted March 8, 2006 Share Posted March 8, 2006 I'm pretty sure the senders are the same 70-late 76. The 77-78 tanks take a far different sender unit (that is very expensive!) and it is mounted in the top of the tank not the side like the earlier ones. Early ones are cheap and you may be able to reuse yours. Get the o-ring from Nissan as they fit best. 70-78 Zs had no fuel lines installed in the sending unit. Feed and return lines are on the bottom side of tank (near dif). Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 9, 2006 Author Share Posted March 9, 2006 Thanks for all of your replies! I will be swaping my gas tank in the next day or so, so well see how well everything works out. Quote Link to comment Share on other sites More sharing options...
qwik240z Posted March 9, 2006 Share Posted March 9, 2006 Thanks for all of your replies! I will be swaping my gas tank in the next day or so, so well see how well everything works out. Let us know how it goes. I have heard that the straps from the 240Z are not long enough for the 75-76 tank. Sure would like to know for sure. Good Luck! Quote Link to comment Share on other sites More sharing options...
spotfitz Posted March 9, 2006 Share Posted March 9, 2006 technicalninja is right. I don't know what I was think with the fuel lines being part of the sender unit. They are not. I was working on a '79 ZX last weekend. Maybe thats where I got mixed up. Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 9, 2006 Author Share Posted March 9, 2006 technicalninja is right. I don't know what I was think with the fuel lines being part of the sender unit. They are not.I was working on a '79 ZX last weekend. Maybe thats where I got mixed up. LOL, Thats ok. I assumed you were confused. I didnt see why they would put vent lines at the BOTTOM of the tank Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 10, 2006 Author Share Posted March 10, 2006 Alright, so I dropped my tank today. The fuel level sender is a direct swap. The tank looks exactly the same size. The only difference is the location of vents and fuel lines. I took a bunch of pics of all the differences, here is a link to the folder containing the pics: http://blucowtech.hopto.org/MyDocs/Media/My%20Pictures/carparts/gas%20tank/ Quote Link to comment Share on other sites More sharing options...
qwik240z Posted March 10, 2006 Share Posted March 10, 2006 I know that Dave, (1tuffZ) did the same swap and he had mentioned that the tank straps are not long enough. From the pictures you posted it looks like the round protruding area on the top of the tank may put the tank lower by about 1". Can you let us know if this will still work with the stock straps? I have a 1975 tank that I am planning on swapping into my 72 and I want to be sure to have all of the correct parts on hand before I start. Do you have the straps from the 75 tank too? are they longer then the 240Z straps? Thanks. Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 11, 2006 Author Share Posted March 11, 2006 I dont have the '75 straps. I was a bit worried about that round area on the top too. Ill let you guys know how it all turns out when I put it on. Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 11, 2006 Share Posted March 11, 2006 I know that Dave' date=' (1tuffZ) did the same swap and he had mentioned that the tank straps are not long enough. From the pictures you posted it looks like the round protruding area on the top of the tank may put the tank lower by about 1". Can you let us know if this will still work with the stock straps? I have a 1975 tank that I am planning on swapping into my 72 and I want to be sure to have all of the correct parts on hand before I start. Do you have the straps from the 75 tank too? are they longer then the 240Z straps? Thanks.[/quote'] The tank straps ARE long enough, but you need the longer J-Bolts to use the stock straps. I haven't tried to use the stock straps with the short bolts, but I doubt it works---you might juuuuust get the threads started, but it will be tough, if that's the case, then once started they thread on easily and will be plenty long, but without tension on them starting them on the short j-bolts is a beyotch! When I saw the long J-Bolts when I snagged the later tank in the JY, I figured I'd snatch them and just cut them down if I needed to in case they were "too long". I didn't need to, thoug the extra length made starting the nuts on them easy peasy lemon squeasy. Other than routing some of the vapor lines, and getting the nuts started, it's a bolt in that doesn't get much easier. I swapped my sender over to the newer tank because it uses a different connector on it. Didn't want to hack anything down there---the sending unit ohm values are the same. Laying the straps down next to each other, they looked similar---so the later cars may have longer bolts for the same reason! Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 11, 2006 Author Share Posted March 11, 2006 The tank straps ARE long enough, but you need the longer J-Bolts to use the stock straps. Yeah, thats what I had suspected. I am going to pick up some longer J-bolts from work today and try to put the tank on tonight, we'll see what happens. As far as the vent lines go, the old ones all went into a collector in the quarter panel then a line runs to the engine bay which was blocked off. My plan is to run one line from the vent in the filler kneck to the larger vent in the tank and then run the smaller vent in the tank up to the engine bay. Then I will run that into the intake manifold so when I am building up boost it will pressurise the tank and help push the gas out. Quote Link to comment Share on other sites More sharing options...
pimp1911 Posted March 11, 2006 Share Posted March 11, 2006 Tank strap question. Anybody know where replacement tank straps can be purchased. This is for a 72 Z. Quote Link to comment Share on other sites More sharing options...
zane9000 Posted March 12, 2006 Author Share Posted March 12, 2006 OK, update time. The stock 73 straps/bolts are about 1.5-2" too short. I am going to go pick up two cable tensioners from the hardware store and use those to tighten the straps to the mounts. Also, the stock fuel send/return lines are each about a size smaller than the 75 lines. To fix this I will be getting some flexible lines of the right size and run it all the way to the front of the car, completely bypassing the hard lines. Quote Link to comment Share on other sites More sharing options...
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